Mitral Valve In Children Research Articles

Euclidean and Shape-Based Analysis of the Dynamic Mitral Annulus in Children using a Novel Open-Source Framework

The dynamic shape of the normal adult mitral annulus has been shown to be important to mitral valve function. However, annular dynamics of the healthy mitral valve in children have yet to be explored. The aim of this study was to model and quantify the shape and major modes of variation of pediatric mitral valve annuli in four phases of the cardiac cycle using transthoracic echocardiography. The mitral valve annuli of 100 children and young adults with normal findings on three-dimensional echocardiography were modeled in four different cardiac phases using the SlicerHeart extension for 3D Slicer. Annular metrics were quantified using SlicerHeart, and optimal normalization to body surface area was explored. Mean annular shapes and the principal components of variation were computed using custom code implemented in a new SlicerHeart module (Annulus Shape Analyzer). Shape was regressed over metrics of age and body surface area, and mean shapes for five age-stratified groups were generated. The ratio of annular height to commissural width of the mitral valve ("saddle shape") changed significantly throughout age for systolic phases (P<.001) but within a narrow range (median range, 0.20-0.25). Annular metrics changed statistically significantly between the diastolic and systolic phases of the cardiac cycle. Visually, the annular shape was maintained with respect to age and body surface area. Principal-component analysis revealed that the pediatric mitral annulus varies primarily in size (mode 1), ratio of annular height to commissural width (mode 2), and sphericity (mode 3). The saddle-shaped mitral annulus is maintained throughout childhood but varies significantly throughout the cardiac cycle. The major modes of variation in the pediatric mitral annulus are due to size, ratio of annular height to commissural width, and sphericity. The generation of age- and size-specific mitral annular shapes may inform the development of appropriately scaled absorbable or expandable mitral annuloplasty rings for children.

The Use of 3D Echocardiography in Surgical Planning of the Mitral Valve in Pediatric Cardiology.

Mitral valve disease in pediatric cardiology is complex and can involve a combination of annular, leaflet, chordae tendineae and papillary muscle abnormalities. Transthoracic two-dimensional echocardiography (2DE) remains the primary diagnostic imaging technique utilized in pediatric surgical planning. However, given that the mitral valve is a three-dimensional (3D) structure, the addition of 3D echocardiography (3DE) to better define the mechanisms of stenosis and/or regurgitation is advantageous. Transthoracic 3DE technology has improved with advances in probe technology and ultrasound scanners, producing images with good spatial resolution and adequate temporal resolution. Specifically, the addition of pediatric 3D transducers with higher frequencies and a smaller footprint provides better 3DE imaging in children. Improved efficiency of 3DE acquisition and analysis allow 3D assessment of the mitral valve to be more easily integrated by the sonographer, the cardiologist and the surgeon in mitral valve assessment. This improvement was also made possible by the postprocessing software optimization. In this method paper, we aim to describe the transthoracic 3DE assessment of the mitral valve in children and its use in the surgical planning of pediatric mitral valve disease. Firstly, the 3DE assessment begins by selecting the correct probe and by obtaining a view of the mitral valve. Then, the appropriate data acquisition method should be selected based on the individual patient. Next, optimization of the data set is critical in order to properly balance spatial and temporal resolution. During live scanning or following acquisition, the data set can be cropped using innovative tools that allow the user to quickly obtain an infinite number of cut planes or volumetric reconstructions. The cardiologist and surgeon can view the mitral valve en face; thus, accurately reconstructing its morphology in order to support medical or surgical planning. Finally, a review of some clinical applications is proposed, showing examples in pediatric mitral valve managements.

Three-Dimensional Mitral Valve Morphology in Children and Young Adults With Marfan Syndrome

Mitral valve (MV) prolapse is common in children with Marfan syndrome (MFS) and is associated with varying degrees of mitral regurgitation (MR). However, the three-dimensional (3D) morphology of the MV in children with MFS and its relation to the degree of MR are not known. The goals of this study were to describe the 3D morphology of the MV in children with MFS and to compare it to that in normal children. Three-dimensional transthoracic echocardiography was performed in 27 patients (3-21years of age) meeting the revised Ghent criteria for MFS and 27 normal children matched by age (±1year). The 3D geometry of the MV apparatus in midsystole was measured, and its association with clinical and two-dimensional echocardiographic parameters was examined. Compared with age-matched control subjects, children with MFS had larger 3D annular areas (P<.02), smaller annular height/commissural width ratios (P<.001), greater billow volumes (P<.001), and smaller tenting heights, areas, and volumes (P<.001 for all). In multivariate modeling, larger leaflet billow volume in MFS was strongly associated with moderate or greater MR (P<.01). Intra- and interuser variability of 3D metrics was acceptable. Children with MFS have flatter and more dilated MV annuli, greater billow volumes, and smaller tenting heights compared with normal control subjects. Larger billow volume is associated with MR. Three-dimensional MV quantification may contribute to the identification of patients with MFS and other connective tissue disorders. Further study of 3D MV geometry and its relation to the clinical progression of MV disease is warranted in this vulnerable population.

Floppy Mitral Valve in Children with Marfan Syndrome

Floppy Mitral Valve in Children with Marfan Syndrome

Implantacja zastawki Melody w pozycję mitralną — u dziecka z nienaprawialnym uszkodzeniem zastawki w przebiegu infekcyjnego zapalenia wsierdzia

We present a case of emergency mitral valve replacement with the first — to the best of our knowledge — use of Melody balloon expandable stented bioprosthesis in a 2-years-old patient with acute endocarditis, subsequent mitral (bicuspid) valve incompetence after aggressive infective destruction, with the symptoms of critical multiorgan failure. The patient with a history of rapid deterioration after 2-weeks-long septicemia in the course of acute endocarditis was operated for life-saving indications. Melody valve was expanded over 16 mm TyShak balloon and implanted into a mitral position (Melody-MVR) with good result. Based on actual knowledge concerning heart valves reconstructions and institutional experience we conclude that infected mitral valve in children should be primary repaired, nevertheless Melody valve could be reasonable considered as a mitral prosthesis in patients with non-reparable conditions.

Mid-term results of mitral valve repair for pure mitral regurgitation in children

The surgery of the mitral valve in children is a particular challenge because of the variety of lesions requiring surgical management, feasibility of conservation of the native valve is the first concern of the surgeon

Feasibility and reproducibility of tissue motion annular displacement of mitral valve in children with and without heart disease

Feasibility and reproducibility of tissue motion annular displacement of mitral valve in children with and without heart disease

Feasibility and reproducibility of tissue motion annular displacement of mitral valve in children with and without heart disease

Feasibility and reproducibility of tissue motion annular displacement of mitral valve in children with and without heart disease

Functional remodeling of floppy mitral valve in children with Marfan syndrome

Functional remodeling of floppy mitral valve in children with Marfan syndrome

Invited Commentary

Alghamdi and associates [1Alghamdi A.A. Yanagawa B. Singh S.K. Horton A. Al-Radi O.O. Caldarone C.A. Balancing stenosis and regurgitation during mitral valve surgery in pediatric patients.Ann Thorac Surg. 2011; 92: 680-684Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar] have highlighted the delicate balance that can be achieved between mitral stenosis and mitral regurgitation when repairing the mitral valve in children in order to achieve a more durable outcome and avoid mitral valve replacement. They show that greater than mild to moderate mitral regurgitation is poorly tolerated and an independent predictor of reoperation or death. The reduction of mitral regurgitation to less than moderate to mild by the creation of mild mitral stenosis makes for a better long-term repair. This approach of avoiding mitral valve replacement at the expense of a less-than-perfect repair, but one that is well tolerated with balanced regurgitation and stenosis, does allow for growth of the patient and removes the risks of anticoagulation with mitral valve replacement. Deferring mitral valve replacement to the older and larger patient allows a bigger valve to be placed. This article deals with patients of a median age of 4 years, with dysplastic valve morphology rather than the complex morphology seen in infancy, such as parachute mitral valve and where multiple obstructive lesions are present on the left side of the heart (Shone syndrome). Patients in the first few months and year of life are almost certainly more challenging than the cohort in article by Alghamdi and colleagues. However, the approach of achieving balanced mitral stenosis and mitral regurgitation, and a repaired valve, is certainly applicable to this younger, more difficult group. Long-term evaluation outcome for these patients should include the ability of the patient to thrive and develop and the lack of development of pulmonary hypertension. The mitral valve hemodynamics were assessed on the operating table under anaesthetic and probably underestimates the degree and severity of mitral stenosis and regurgitation. However, because this assessment mode was uniformly applied to all patients, it would seem to be acceptable. Mitral valve repair in young patients, particularly in the first few months of life, is difficult and challenging. The underlying morphology is complex, and individual variation in morphology from patient to patient makes each case a separate challenge. Although this report is in older children, the concept that a balanced repair that leaves mild to moderate valve regurgitation together with mild mitral stenosis to compensate for what otherwise would be severe mitral regurgitation, with a very bad outcome, seems eminently sensible. Balancing Stenosis and Regurgitation During Mitral Valve Surgery in Pediatric PatientsThe Annals of Thoracic SurgeryVol. 92Issue 2PreviewThe objectives of this study were to evaluate the composite outcome of reoperation or death for mitral valve repair and replacement and to determine the relative importance of regurgitation and stenosis during mitral valve repair to guide intraoperative decision making. Full-Text PDF

Aortic and mitral valve replacement in children: current options and outcomes

The aortic and mitral valve in children can be affected by several disease pathologies, frequently necessitating intervention. Congenital valve disease is the most frequent pathology in Europe and ...

Anterior leaflet on the leash: unusual cause of congenital severe mitral regurgitation

Isolated-congenital mitral regurgitation is infrequently seen in adults. In its mechanism, the entire mitral apparatus or different components separately can play a role [Gallet B. Use of echocardiography in mitral regurgitation for the assessment of its mechanism and aetiology for the morphological analysis of the mitral valve. Ann Cardiol Angeiol 2003;52(2):70-7; Valdes-Cruz LM, O'Cayre R. Echocardiographic Diagnosis of Congenital Heart Disease. Philadelphia, NY: Lippincott-Raven; 1998; Carpentier A, Branchini B, Cour JC, Asfaou E, Villani M, Deloche A et al. Congenital malformations of the mitral valve in children. Pathology and surgical treatment. J Thorac Cardiovasc Surg 1976;72: 854-66]. We report a case of an unusual congenital mitral regurgitation resulting from restriction of the mitral leaflet caused by thick fibrotic tissue connecting left atrial roof and the anterior leaflet precluding sufficient coaptation. To the best of our knowledge, this pathology has never been reported before.

Surgical Repair of the Mitral Valve in Children With Dilated Cardiomyopathy and Mitral Regurgitation

Significant mitral regurgitation is known to exacerbate left ventricular dysfunction in dilated cardiomyopathy. Although intervention on the regurgitant mitral valve is frequently described in adults, there is little pediatric data. Five children (aged 3 months to 4 years) with dilated cardiomyopathy and mitral regurgitation underwent mitral valve repair between January 1999 and January 2007 at our institution. All had mitral regurgitation graded as moderate to severe, with ejection fractions of 35% to 60% (median 53%). There were no deaths; all children were weaned from cardiopulmonary bypass; 1 child required cardiac transplantation 3 weeks after repair. After surgery, mitral regurgitation was moderate in 1 patient, mild in 2 patients, and trivial in 2 patients. The 4 successful cases showed an improvement in functional status at latest follow-up (range, 8 years to 4 months): all were asymptomatic (4 children had preoperative symptoms). Successful cases showed a decreased left atrial dimension (mean z-score 3.8 to 2.6) and a decreased left ventricular end-diastolic diameter (mean 6.9 +/- 1.6 to 5.4 +/- 1.2). Ejection fraction and left ventricular end-systolic index did not show an improvement and declined in some cases. We conclude that repair of the mitral valve is feasible in children with dilated cardiomyopathy and acquired mitral regurgitation. Most of the children demonstrated decreased left ventricular chamber sizes and an improved functional status. Although this operation improves symptoms, it is not clear whether it postpones or abrogates the need for cardiac transplantation.

Invited Commentary

The authors [1Walsh M.A. Benson L.N. Dipchand A.I. et al.Surgical repair of the mitral valve in children with dilated cardiomyopathy and mitral regurgitation.Ann Thorac Surg. 2008; 85: 2085-2089Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar] report their experience with dilated cardiomyopathy and mitral regurgitation in 5 children who then underwent mitral valve surgical repairs. Four of the 5 patients demonstrated a favorable response to mitral valve repair, with 1 patient requiring cardiac transplantation. The authors conclude that “repair of the mitral valve is safe and feasible in children with dilated cardiomyopathy and acquired mitral regurgitation.” There are several limitations of this series that are purely a product of the relative rarity of this situation. These limitations include the small number of patients, the limited duration of follow-up, and the absence of a parallel medical cohort. As a consequence, it is difficult to make any definitive conclusions, and the authors have appropriately softened their own conclusions. What one would really like to know is whether mitral valve repair benefits these patients relative to the natural history of the disease. Will mitral valve repair reduce the need for transplantation? Does a delay in mitral valve repair place patients at greater risk for needing transplantation and if so, what are the criteria for intervention? There are also some intriguing aspects of cardiac physiology embedded in the authors' data. Specifically, the data demonstrate that mitral valve repair resulted in decreases in left ventricular end-diastolic and left atrial dimensions, which the authors construe as favorable, but at the expense of some decrement in ejection fraction. Will this decrease in ejection fraction result in an “intervened history” that will be better or possibly worse than the natural history of the disease? These questions are currently not able to be answered due to the limitations previously cited. Having put forth these comments and critiques, the authors should be commended for endeavoring this work. This is a difficult cohort of patients, and one in which the natural history is not very favorable. The fact that they have suggested this treatment modality should open the door to define the appropriate questions and eventually lead to answers. After all, this is how progress is made. Surgical Repair of the Mitral Valve in Children With Dilated Cardiomyopathy and Mitral RegurgitationThe Annals of Thoracic SurgeryVol. 85Issue 6PreviewSignificant mitral regurgitation is known to exacerbate left ventricular dysfunction in dilated cardiomyopathy. Although intervention on the regurgitant mitral valve is frequently described in adults, there is little pediatric data. Full-Text PDF

A real-time 3-dimensional digital Doppler method for measurement of flow rate and volume through mitral valve in children: A validation study compared with magnetic resonance imaging

We developed and assessed a real-time 3-dimensional (3D) digital Doppler method for measurement of flow volumes through the mitral valve in children. A total of 13 children (aged 10.46 +/- 2.5 years; 8 boys/5 girls) were enrolled. An ultrasound system (Sonos 7500, Philips, Andover, Mass) was used to acquire raw 3D velocity data for flow measurement based on Gaussian control surface theorem [flow (mL/s) = mean velocity x flow area]. Stroke volume (SV) measured by real-time 3D digital Doppler with the control surface at the mitral valve annulus or orifice was compared with the SV by phase velocity cine magnetic resonance imaging (MRI) at the ascending aorta and by left ventricular volumetric MRI measurement. The best correlation and agreement were seen at the mitral valve orifice by real-time 3D digital Doppler compared with SV by phase velocity cine MRI at the ascending aorta (r = 0.92, mean difference = -5.2 +/- 12.0 mL) and SV by left ventricular volumetric MRI measurement (r = 0.94, mean difference = -0.2 +/- 10.3 mL).

Mitral valve replacement in children: Evolution and outcomes of a 40-year experience

Background. The ideal prosthesis for mitral valve replacement (MVR) in children remains controversial. The study aim was to review of evolution and outcomes of our 40-year experience with MVR in children. Methods. Since 1963, 75 patients (mean age 9.2 years) have undergone a total of 103 MVR operations. The etiology for valve disease was congenital in 55% of patients, rheumatic in 35%, endocarditis in 8%, and myxomatous in 2%. Xenograft bioprosthesis ( n = 13) and mechanical valves ( n = 58) were used in 71 patients at initial MVR. Since 2002, four patients have undergone MVR using a pulmonary autograft (Ross MVR). Results. Hospital mortality was 9%. Mean follow-up was 7.8 years (range; 2 months to 30 years). Twenty-three patients required reoperations (34%) after the initial MVR. Actuarial freedom from reoperation at 30 years was 47%. There were 16 late deaths and four patients underwent heart transplantation. Overall 30-year survival was 69%. Mortality for children under 2 years versus over 2 years was 47% versus 26% ( P = 0.02), for atrioventricular septal defect versus other pathology mortality was 54% versus 26% ( P = 0.05), and for those operated before versus after 1980 it was 57% versus 20% ( P = 0.003). Conclusions. MVR is the only surgical option for nonrepairable mitral valve in children. Until recently we have favored mechanical MVR for children with failed reconstructive surgery. Our recent experience with the Ross MVR and aortic homograft MVR has allowed us to offer select patients the possibility of a more durable tissue valve without the need for long-term anticoagulation. The Ross MVR is particularly attractive in young female patients.

The distance from the Amplatzer septal occluder to the mitral valve in patients undergoing interventional closure of defects in the oval fossa increases with growth of the patient

The Amplatzer septal occluder is an alternative to operative closure of atrial septal defects within the oval fossa. An issue when deploying the device is its distance from the mitral valve. The purpose of this study is to determine how this distance changes with growth of the patient. We identified, through a review of charts, all patients undergoing closure of defects within the oval fossa by insertion of an Amplatzer septal occluder. Data were obtained from the echocardiogram 24 hours after closure, and at most recent follow-up, including left ventricular end-diastolic diameter, left atrial diameter, degree of mitral valvar regurgitation, body surface area, and distance from the device to the mitral valve. We divided the patients into 2 groups based upon change in body surface area. The first group had an increase in body surface area of at least 10%. All others were in the second group. We inserted 55 Amplatzer septal occluders in 54 patients. Of these we excluded 17 patients, 1 because quality of images was inadequate, 1 who underwent placement of 2 devices, 1 in whom the device embolised to the left ventricle the day after deployment, and 14 who have not yet had a follow-up echocardiogram. The group which exhibited an increase in body surface area of greater than 10% demonstrated an increase in distance from the device to the mitral valve, left ventricular end-diastolic, and left atrial diameters. Those who did not undergo significant growth had no increase in distance from the device to the mitral valve, but did have an increase in left atrial and left ventricular end-diastolic diameters. No patient developed mitral regurgitation. We conclude that, when deploying an Amplatzer septal occluder close to the mitral valve in children, the distance from the device to the mitral valve can be expected to increase with growth of the patient.

Overlapping annuloplasty of the mitral valve in children

Harmonious reduction of the posterior annulus of the mitral valve can be a useful adjunct to obtain complete valve competence in case of annular dilatation. We present a technique with the use of two resorbable sutures that overlap over the middle third of the posterior annulus that was used in 10 children with good short-term results. Resorption of the sutures should permit subsequent normal growth of the mitral valve. If the primary cause of valvular regurgitation was corrected, it can be expected that the repair will remain stable after resorption of the sutures.

Use of expanded polytetrafluoroethylene sutures as artificial tendinous cords in children with congenital mitral regurgitation.

To determine the efficacy in the intermediate term of artificial cords inserted in children with congenital mitral regurgitation. We reconstructed the tendinous cords using expanded polytetrafluoroethylene (ePTFE) sutures in 11 children with severe mitral regurgitation. In these patients, the aortic (anterior) leaflet of the mitral valve had been markedly prolapsed, the tendinous cords being partially lacking in seven, and elongated in the remaining four. In addition, one of the papillary muscles was hypoplastic in five and absent in three. The number of artificial cords constructed varied from two to six. Conventional annuloplasty was performed in all to plicate the dilated annular attachment of the valve. Ventricular septal defect was present in four patients, and other associated malformations in another two. Age at operation ranged from 9 months to 9 years old, with a mean of 4.5 years. All patients survived the operation. No reoperation has been needed thus far. No complications were encountered related to the use of the prosthetic materials or anticoagulation. As judged by echocardiography, regurgitation became trivial or slight immediately after the repair. In two patients, however, regurgitation recurred within 1 year of the operation. Coaptation between the leaflets was maintained by a compensatory growth at the site of attachment of the artificial cords. Catheterization demonstrated significant improvements in the end-diastolic volume of the left ventricle. Expanded polytetrafluoroethylene sutures can be used as artificial cords when attempting to repair the malformed mitral valve in children, providing excellent results in the short- and the intermediate-term after the surgical procedure.

Homograft replacement of mitral valve in children

Background. Recent reports have demonstrated successful early outcomes using mitral valve homografts in adults. We report our early results after homograft mitral valve replacement in 4 children with previous atrioventricular septal defects, previous placement of a prosthetic valve, and rheumatic valvular disease. Methods. Between May 1996 and June 1997, 4 children (ages 5, 11, 13, and 15 years) underwent mitral valve replacement with cryopreserved mitral valve homografts at our institution. Preoperative echocardiography confirmed moderately severe to severe mitral regurgitation, stenosis, or both in all 4 patients. Results. Successful homograft valve replacement was achieved in all 4 patients. Based on symptoms, physical examinations, and echocardiographic follow-up, all four homograft mitral valves are functioning well with normal hemodynamics. None of these patients are receiving warfarin. Follow-up has been limited to 10 months. Conclusions. In children requiring mitral valve replacement, the use of mitral valve homografts offers advantages over prosthetic valves, such as the avoidance of complications associated with thrombosis and anticoagulation. Homograft mitral valve replacement is technically feasible in children with congenital and rheumatic heart disease and previous prosthetic valves.